The present invention relates to a method for forming a breast prosthesis, and in particular to a method for forming a breast prosthesis that has a precisely uniform surface thickness and is shaped to mirror the existing breast when held in a brassiere. To form the mold for the prosthesis, a plastic sheet is formed into the shape of the natural breast. Once molds are made using this plastic sheet, the breast prosthesis outer surface may be formed within the molds. This outer surface is then turned inside out to form the outer surface for a breast prosthesis that is the mirror image of the natural breast.
The purpose of the disclosed invention is to create a comfortable, natural-appearing breast prosthesis for a patient that has lost one of her natural breasts. Typically the natural breast is lost as a result of a mastectomy procedure, although this invention may be utilized regardless of the reason the patient requires the prosthesis. A breast prosthesis should ideally mirror the size, shape, and texture of the remaining natural breast as closely as possible. In this way the patient's goal of appearing to have two natural breasts is most nearly achieved. Since the breast prosthesis is generally only worn while the patient is wearing a brassiere or other support garment, the shape of the breast prosthesis should mirror the shape of the patient's remaining natural breast while that breast is supported.
Other methods for forming a breast prosthesis shaped to mirror an existing natural breast are known in the art. U.S. Pat. No. 2,580,264 to Wright, et al. discloses a method of producing a mold for an artificial breast by turning a mold taken from the existing breast inside out. In the Wright, et al. process, a plaster of Paris mold is taken of the existing breast. A coating of quick-drying liquid latex rubber is then applied inside the plaster of Paris mold. When dried, the latex rubber forms a flexible casing that may be removed from the plaster of Paris mold. The latex rubber casing is turned inside out to form a mold for the artificial breast that will be a mirror image of the existing breast.
U.S. Pat. No. 5,527,359 to Nakamura et al. also discloses a method of producing a mold for an artificial breast by turning a mold taken from the existing breast inside out. In the Nakamura et al. process, a model of the existing breast is formed using aluminum foil. The aluminum model is then filled with plaster to form a positive model of the existing breast. The positive model is then coated with aluminum foil reinforced by thin adhesive taping. The aluminum foil/adhesive taping complex is then turned inside out to form a negative model of the artificial breast.
Other methods are also known for forming a breast prosthesis in the shape of a breast held in place by a support garment. U.S. Pat. No. 4,086,666 to Vaskys et al. discloses a method for forming a breast prosthesis in the shape of a supported breast. In addition to using a cast made of the patient's chest while not wearing a brassiere, a cast is also made of the patient's chest while wearing a brassiere. The negative cast is simply formed over the brassiere itself. A sculptor then uses the positive cast of the supported breast/brassiere combination to help visualize the appearance of the supported breast. Alternatively, Vaskys et al. discloses that measurements may be made of the patient's remaining natural breast while the patient is wearing a brassiere to assist the sculptor in forming a prosthesis in the shape of a supported breast.
U.S. Pat. No. 4,600,551 to Erb discloses a method for producing a breast prosthesis that is symmetrical to the shape of the remaining natural breast while that breast is held in a zero-gravity state. After a molding material is applied to the natural breast, the patient is immersed in a liquid that is of a density essentially equivalent to the density of the natural breast. The mold then cures while the breast is suspended in the liquid. The process thus results in a prosthesis that does not require the artistic interpretation of a sculptor to remove the effects of gravitational stress. However, Erb discloses that the shape of the breast in a zero-gravity state does not strictly conform to the shape of the breast while supported in a brassiere.
Erb also discloses a method of forming a breast prosthesis using a mold formed from a breast supported by a half-brassiere. The half-brassiere is taped to the patient's chest wall and a mold material is formed over the natural breast and brassiere. This approach results in a mold that reflects not the texture of the natural breast only, but also the texture of the brassiere and supporting tape, and thus requires the use of a sculptor in forming the prosthesis.
The prior art methods of forming a breast prosthesis each have a number of disadvantages. First, some of these methods require a human sculptor to form molds for the prosthesis from models. The addition of a sculptor greatly increases the cost and time required for the production of a breast prosthesis. In addition, a human is inherently incapable of exactly reproducing the shape of the existing natural breast in mirror-image form to create a precisely accurate mirror-image prosthesis. Instead, a human must rely on his or her artistic abilities, which inevitably introduces some error into the process.
Another disadvantage of the prior art methods is that the exterior surface of the resulting breast prosthesis will not be of uniform thickness. Simply pouring or painting a curable material onto a smooth surface will result in a cured material that is smooth on only the side that is in contact with the smooth surface. The other side of the cured material will inevitably be wavy, resulting in a cured material of nonuniform thickness. The thickness and consistency of the prosthesis surface is critical for several reasons. First, a material that has thin spots may tend to "balloon" at the thin points, resulting in a misshapen prosthesis. On the other hand, a material that is too thick will result in a prosthesis that does not feel to the touch like a natural breast. Finally, a prosthesis that has an exterior surface of nonuniform thickness will not be as nearly symmetrical with the remaining natural breast as would otherwise be possible using a consistently flat exterior surface material.
Still another disadvantage of the prior art methods for forming a breast prosthesis is the inability to form an accurate image of a breast held in a brassiere or other support garment. This shape is preferred by patients because the prosthesis will typically be worn only while the patient is wearing a support garment. Since a natural breast necessarily sags somewhat due to gravity, a prosthesis formed in the shape of a natural breast will not be symmetrical to the remaining natural breast when a support garment is worn. The Erb method of forming a breast prosthesis while the natural breast is suspended in a controlled-density liquid is awkward, expensive, and would likely cause considerable embarrassment to the patient who must enter this liquid while her upper body is exposed. Moreover, the Erb disclosure indicates that the shape of a breast in this zero-gravity state does not correspond to the shape of a breast held in a supported garment, so the resulting prosthesis would still not mirror the patient's remaining natural breast. The other method disclosed by Erb, that of forming a mold over the patient's remaining natural breast while wearing a half-brassiere, requires additional work by an artist to remove the effects of the brassiere on the mold, which would increase the cost and time required to construct the prosthesis.